A. Field of the Invention
This invention relates to a security element for security papers, value documents and the like with at least one microstructure which has a visual appearance that is viewing angle-dependent in transmission.
B. Related Art
Data carriers, such as value documents or identification documents, or other objects of value, such as branded articles, are often provided for safeguarding purposes with security elements which permit a verification of the authenticity of the data carriers and which at the same time serve as protection from unauthorized reproduction. The security elements can be configured for example in the form of a security thread embedded in a bank note, a tear thread for product packages, an applied security strip, a cover foil for a bank note with a through opening, or a self-supporting transfer element, such as a patch or a label, which after being produced is applied to a value document.
A special role in authentication assurance is played by security elements with viewing angle-dependent effects, because these cannot be reproduced even with the most modern copiers. The security elements are equipped here with optically variable elements which convey a different pictorial impression to the viewer from different viewing angles, showing for example a different color impression or brightness impression and/or a different graphic motif depending on the viewing angle.
For this purpose, there has been proposed in the print WO 2008/049533 A2 a see-through security element with at least one microstructure with an appearance that is viewing angle-dependent in transmission, wherein the at least one microstructure is formed from an arrangement of a multiplicity of structure elements with a characteristic structure spacing of 1 μm or more and wherein the see-through security element has a total thickness of 50 μm or less.
On these premises, the invention is based on the object of stating a generic security element which, on the one hand, is thin enough to be able to be used in the security-paper and value-document sector and which, on the other hand, has not only high forgery resistance but also a visually attractive appearance, in order to be perceived, heeded and remembered as a security feature by the user.